Synchronizing clock system



8, L. s- HARRISON SYNCHRONI Z ING CLOCK SYSTEM Filed NOV. 29, 1924 5Sheets-Shea? l @WM5/527W@ if @W5 OCt. 8, 1929. ,v L Q HARR|SQN y1,730,504

SYNCHRONIZING CLOCK SYSTEM Filed NOV. 29, 1924 3 Sheets-Sheet 2 Oct. 8,l 929.

L. s. HARRISON SYNCHRONIZING CLOCK SYSTEM Filed NOV. 29, 1924 3Sheets-Sheet Patented Oct. 8 1929 UNITED STATES PATENT OFFICE LAURENCES. HARRISON, F NEW YORK, N. Y., ASSIGNOR TO TNTERNATIONAL TIME RECORDINGCOMPANY OF NEW YORK, OF ENDICOTT, NEW YORK, A CORPORATION OF NEW YORKSYNCHRONIZING CLOCK SYSTEM Application led November 29, 1924. Serial No.753,008.

My invention relates to clock systems, and it has particular relation tosuch systems as may be energized from alternating-current sources.

One object of my invention is to provide an alternating-current clocksystem which shall not only reset automatically but which shall also beself-synchronizing.

Another object of my invention is to provide a synchronizing clocksystem, wherein an increased alternating-current voltage is employed toaccelerate and reset all secondary clocks after a failure of the sourceof energy.

A further object of my invention is to provide a synchronizing clocksystem, wherein a single conductor common to al l the secondary clocksfurnishes synchronizing currents at regular intervals to correct suchsecondary clocks as may have departed fr om synchronism with a mainsynchronizing clock. V

A still further object of my invention is to provide a secondary clockmechanism which shall be accelerated if slow and retarded if fast by therespective reversals of electric currents through a regulating coil.

A still further object of my invention is to provide a secondary clockmovement having a time rate which may be varied by ad]usting theposition of a permanent magnet with respect to a rotating member such asconstitutes the actuating disk of an alternating-current watt-hourmeter.

Vith these and other objects and applications in mind, my inventionfurther consists in the details of construction and operation andcircuit arrangement, hereinafter setforth in the accompanyingdescription, claims and drawings, wherein,

Fig. 1 is a diagrammatic view of an alterhating-current, automaticresetting, selfsynchronizing clock system embodying my invention;

Fig. 2 is a perspective view of the actuating motor for the mainsynchronizing and secondary clocks;

Fig. 3 is an enlarged detail perspective View of the structure of Fig.2, showing the niinute shaft and associated switch mechanism;

Fig. 4 is a similar view of the mechanism interconnecting the mainsynchronizing clock and the master clock as well as certain switchesactuated thereby;

Fig. 5 is a perspective view of the structure of Fig. 4 viewed from theright; and

Fig. 6 is a sequence chart illustrating the operating periods of thesecondary and mainsynchronizing clock control-switches.

In the illustrated form of my invention shown in Fig. 1 of the drawing,a source of alternatin -current energy (not shown) is connected yconductors 1 and 2 to the opposite terminals 3 and 4, respectively, ofan auto-transformer vhaving an adjustable intermediate tap connection 6.A main power circuit 7 for a main synchronizing clock 8 and a pluralityof secondary clocks 9, comprises a conductor 11, which extends from theterminal 3 of the auto-transformer 5, and a conductor 12. The conductor12 may be connected either to the intermediate tap connection 6 or tothe terminal connection 4 of the auto-transformer 5 through mechanicallyconnected switches 13 and 14 and conductors 15 and 16, respectively.

My invention contemplates an actuating motor 17 for each of thesecondary clocks 9 and the main synchronizing clock 8 of t-heconstruction shown in Fig. 2, wherein a potential coil 18 and aregulating coil 19 are mounted on a laminated core 21 in such manner asto establish magnetic fluxes which at electrical' degrees out of phase.The coils 18 and 19 are spaced suiliciently to provide an air gap 22,wherein a disk 23 may be positioned. The disk 23 is revolubly mounted ona vertical shaft 24 and it is connected to the usual clock gear train 25of which only a worm-and-wheel are shown. The disk 23 is so positionedwith respect to the windings 18 and 19 that edd currents are inducedtherein with the resu t that a torque is established tending to rotatethe disk 23.

Aresistor 26 and a second regulating coil 27 may also be mounted on thecore 21. As shown in Fig. 1, the terminals of the potential coil 18 areconnected by conductors 28 and 29 to the terminals of the regulatingcoil 19, whereby the same may be connected in multiple-circuit relation,and the resistor 26 is inserted in the conductor 28.

The electrical constants of the coils 18 and 19 are such that the disk23 operates at the rate of live to ten revolutions per'minute,corresponding to normal clock time rate. The disk 23 may rotate before asmall aperture (not shown) whereby the'clocktime rate may be easilychecked by noting the passage of a marker 31 across the aperture.

The rate of rotation of the disk 23 may be controlled by means of adamping magnet 32, the poles 33 of which may be adjusted radial'- lyover the disk 23 and secured in any desired position. The terminals of`the potential coil 18 may be connected by conductors 34 and 35 to theconductors 12 and 11, respectively, of the main power circuit 7.

` Should there be an interruption in the current supply to thetransformer 5 or should the voltage or frequency of the alternatingcurrents vary, resulting in a departure o1 the secondary clocks 9 andthe main synchronizing clock 8 from their normal time rate, my inventionembodies means for automatically advancing, at a relatively high rate,upon a resumption of normal current iow, the hands of the secondary andmain synchronizing clocks to normal or correct time position. To thisend, I provide a cooperating master clock 36, a driven shaft 37 of whichis journaled on a frame 38.

A member 39 which is rigidly secured to a master clock shaft 37, isprovided on one face 41 (Fig.v 5) with an insulating sleeve 42 havingcollector rings 43 and 44, the latter serving to connect electricallyrelatively movable contact members 45 and 46 to stationary brushes (notshown). The contact member 45 is rigidly secured to face 41 of themember 39 near the outer periphery thereof.

The co-acting movable contact member 46 is positioned on one end of anarm 47 which is pivotally mounted on a pin 48 extending from the face41. A spring 49 cooperating with t-he operating arm 47 causes a.l quickmake-and-break between the co-acting contact members 45 and 46. The arm47 may be provided with a slot 51 adapted tonreceive one end' 52 of apin 53,'an opposite end 54 of ,which extends through a slot 55 in themember 39 and is rigidly secured to an arm.

56 pivoted at 57. A spring 58 tends to cause an end portion 59 to engagean abutment 6l,

in which position the contactmembers 45 and 46 are disengaged, (Figs. 4and 5). W'hen the arm 56 is moved from the position shown in Fig. 4, themovable contact member 46 is actuated into engagement with the contactmember 45 against the force of the spring 58.

In order to cause the opening of the contact members 45 and 46 when themain synchronizing clock 8 departs from synchronism with the masterclock 36, the following described mechanism is-provided. A driven shaft62 of the main synchronizing clock 8 is j ournaled in the supportingbracket 38 and it is operatively associated by means of gearing 63 witha gear-wheel member 64 loosely mounted on the end of theA master clockshaft 37 between the supporting bracket 38 and the member 39. Thegear-wheel member 64 is provided with oppositely extending. arms 65 and66, the latter carrying a counter-balance and the former having alateral eXtens'ion 67 providing a mounting for a latch 68.

The latch 68 is so disposed that it normally engages the shoulder 59 ofthe arm 56, causing the contact members 45 and 46 to be in engagement,but permitting shoulder 59 of arm 56 to pass ahead in advance of latch"68 when the main synchronizing clock departs from synchronism with themaster clock 36. This, however, will not occur until main synchronizingclock 8 becomes later than the master clock -in time and the latch 68 isbehind the shoulder 59 of arm 56. The normal engagement between "thelatch 68 and the shoulder 59 while the main synchronizing Vclock and themaster clock are in synchronism may be eiiected by so designing theregulating coil 19 of the main synchronizing' clock 8 that it rotates ata slightly higher time rate than the master clock 36.

As shown in Fig. 1, the contact member 45 is connected by a conductor 69and a conductor 7 0, to the terminal 3 of the transformer 5. The contactmember 46 is connected by a conductor 71 and a conductor 15 to theintermediate tap connection 6. The conductor 71 includes an actuatingwinding 72 for the mechanical switches 13 and 14 whereby the same may beactuated from their normal positions shown in the drawings.

When the main synchronizin clock 8 and the master clock 36 are in syncronism, the latch 68 is in engagement with the shoulder 59 of the lever56, causing the contact member 46 to engage the contact member 45. Theclosed circuit thus formed extends from the terminal connection 3 of thetransformer 5 through vthe conductors andl 69, co-acting contact members45 and 46, the conductor 71, the actuating winding 72 and the conductor15 to the intermediate tap connection 6. The effect of energizing theactuating winding 72 is to cause the closing of switch 1 3 and theopening of switch 14, whereby the conductor 12, of the power supplycircuit 7, may be connected to the intermediate tap connection 6. Thuscurrents of relatively low voltage are normally supplied to the mainpower circuit 7, thevoltage being just sufficient to cause the clocktime rate of the secondary clocks 9 and the main synchronizing clock 8stance, with a lowering of the voltage supply to the transformer 5, therate of movement of the follow-up member 64 would not coincide with thatof the member 39, with the result that shoulder 59 of the arm 56 wouldnot engage the latch 68 and the pin 53,.under the orce of the spring 58,would cause the arm 47 to move so as to disengage the contact membersand 46, whereupon the actuating winding 72 of the switches 13 and 14would become deenergized. The switch 13 then opens by gravity,disconnecting the conductor 1.2 from the conductor 15, while the switch14 closes to connect the conductor 12 to the 'conductor 16. The closingof the switch 14 thus causes an increased voltage to be impressed on themain power circuit conductors 11 and 12 which corresponds to the fullvoltage of the transformer 5. The effect of the increased voltage on theactuating motors 17 of the main synchronizing clock 8 and the secondaryclocks 9 is to increase the rate of operation thereof, which continuesuntil the main synchronizing clock 8 is in synchronism with the masterclock 36, and, if the original 4 cause of the departure from synchronismhas been removed, then the contact member 46 is held in engagement withthe contact member 45 and currents of normal voltage are again suppliedto the conductors 11 and 12 of the main power circuit 7.

Synchronsm of secondary clocks 'with maia synchronizing clock Myinvention further embodies means, whereby the secondary clocks 9 may bebrought into synchronism with the main synn chronizing clock 8 upon adeparture therefrom. To this end, I provide a synchronizing conductor 73which is connected by relatively movable Contact members 74 and 7 5 of arelay 76 to movable contact members 77 and 78 of the switches 13 and 14.The cooperating contact members 79 and 81 of the switches 13 and 14 arerespectively connected to the con-v ductors 15 and 16. The operation ofthe relay 76 may be controlled by means of switches 8 and 83. The switch83, which comprises movabl contact members 84 85, and 86, may beembodied in the form shown in Fig. 4, wherein the several contactmembers are mounted on arms 87, 88 and 89 having a common pivot rod 91supported in the bracket 38. These arms are so disposed as to engage theperipheries of actuating cams 92, 93 and 94, respectively, which aremounted on the shaft 62.

The parts just described are so designed that the switch 83 operatesregularly at intervals of one-half hour to effect the energization ofthe synchronizing conductor 7 3 when contacts 85 and 86 are incontacting relation, the energization period or interval continuing forten minutes. The energization period is concluded in a manner which willbe deinterval is accurately determined, pre erably yby a switch, 82.

The switch 82 comprises movable contact members 96 and 97 which may beactuated by the main synchronizing clock 8 at one minute intervals inthe same manner as the several contact members of the switch 83.

Referring to`Fig. 1, an actuating winding 98 of the relay 76 has oneterminal 99 connected through a conductor 101, which includes a resistor102, to the conductor 70 and transformer terminal connection 3. Aremaining terminal 103 of the actuating Winding98 is connected through aconductor 104, the contact members 96 and 97, a conductor 105, thecontact members 85 and 86 of the switch 83, a conductor 106, and theconductor 15, to the intermediate ta connection 6. Assuming the contactmem ers 85 and 86 just actuated into engagement, the actuating winding98 is energized, causing the engagement of the contact members 74 and 75and the resulting energization of the conductor 73 at a voltagedepending upon whether theconductor 12 is connected to the terminalconnection 4 or the intermediate tap connection 6 of the transformer 5.If the main synchronizingclock 8 and the master clock 36 are insynchronism, then the latter connection obtains.

The relay 76 also comprises contact members 107 and 108, the latterbeing mechanically connected to the contact member 75, whereby theswitch 82 and Contact members 85, 86 of switch 83 may be shuntedfollowing the initial operation thereof to cause the energization of therelay actuating winding`98. To this end, the contact member 107 isconnected to the terminal 103 of the actuating winding 98 and thecontact member 108 is connected by a conductor 109 to the conductor 15.Hence, it may be seen that the contact members 85,

86 of switch 83 now exert no control over the energizing winding 98,since the currents traverse a circuit including the conductor 109 andthecontact members 107 and 108, rather than a circuit including conductor106. the contact members 85 and 86, conductor 105, the switch 82, andthe conductor 104.

When the conductor 73 has been vthus energized for a period of tenminutes corresponding to the interval m in Figf6, the movable contactmember 85 is actuated into engage ment with the movable contact member84 to complete a shunt circuit around the relay actuating winding98,'said shunt circuit including the conductor 104, the switch 82, theconductor 105, contacts84 and 85 and a conductor 110, which extends fromthe movable i 1"' contact member 84 to the terminal 99- of the actuatingwinding 98. The consequent deenergization of the actuating winding 98results in the opening ofthe relay 76 and the disengagement of theco-acting contact members 74, 75 and107, 108. Contacts 84 and .85 arethen opened and the movable contact members of the switch 83 aremaintained out of engagement with each other until the foregoing cycleis again repeated at the end of twenty minutes. l

As hereinbefore noted, each of the secondary clocks is provided with thecorrection coil 27 which has sufficient ampere-turns to produce a-torquethree to four times as great as that established by the regulating coil19. In order thatthe coil 27 may be energized when it is necessary tobring one of the secondary clocks 9 in synchronism with the mainsynchronizing clock 8, I provide a switch 111 which is directly actuatedby the secondary clock mechanism. The switch mechanism 111 comprises apair of mechanically interlocked switch -units 112 and 113.

The switch unit 112 comprises a movable arm 114 carrying contact members115 and 116 on the respective ends thereof which coact with contactmembers 117 and 118, respectively. The switch unit 113 similarlycomprises a movable arm 119 carrying contact members 121 and 122 whichrespectively engage co-acting contact members 123 and 124. The contactmembers 117 and 123 may be connected by a conductor 125 which extends toone terminal .of the accelerating and retarding coil 27. A remainingterminal of the latter is connected by a conductor 126 to the con-- tactmembers 12'4 and 118. The movable contact members 115 and 116 of theswitch unit 112 may be connected by a conductor 127 .to the conductor 73and the movable contact members 121 and 122 of the switch unit 113 maybe connected by conductor 128 to the conductor 35. v

As shown in Fig. 3 of the drawing, the mechanical design of the switchunits V112 and 113 as well as the actuating means therefor is similar tothat of the switch 83 shown in Fig. 4, the actuating means being aseriesof cams 129 which are mounted on a minute shaft 131 of each secondaryclock 9. The shaft 131 may be provided with a shoulder 132 adapted tocooperate with a locking pawl 133 in such manner as to prevent a reversemovement of the'clock mechanism as might possibly occur when thecorrection coil 27 is so f,contact arms 114 and 119 to assume theposition shown in Fig. 1 of the drawing thereby completing a cycle ofthree successive positions.

Assuming the switch units 112 and 113 in the position shown in Fig. 1, acircuit extends from the synchronizing conductor 73 through theconductor 127, the co-acting Contact members 115 and 117, the conductor125, the regulating coil 27, the conductor 126, the co-actingcontactmembers 122 and 124, the conductor 128 and conductor 35 to theconductor-11, of the main power circuit 7, thus permitting currents totraverse the winding 27 so as to cause an increase in the effectiveflux. lVhen the switch units 112 and 113 are actuated into a positionwherein the co-acting contact members 118, 116 and 121, 123 are inengagement, currents are caused to traverse the regulating cioil so asto cause a decrease in the elective As shown in Fig. 6, the operatingperiods and y of the switch units 112'and 113 are so related to theenergizing period m of the synchronizing conductor 73 that if thesecondary clocks 9 are in synchronism with the main synchronizing clock8, the regulating coil 27 is connected to the conductor 73 only duringthe period of deenergization of the conductor 73. However, should one ofthe secondary clocks 9 be slow with respect to the main synchronizingclock 8, then the operation period ae during which the regulating coil27 is connected the conductor 73 overlaps the energizing. period m sothat the movement of said secondary clock is accelerated until it is insynchronism with the main synchronizing cloclc 8.

' Should the secondary clock 9 be fast, then the eperating period g/ ofthe switch units 112 and 113 overlaps the 'energization periodm of theconductor 73, thereby causing a reverse energization of the regulatingcoil 27 and hence an opposite or retarding effect on the secondary clockmechanism. Thus it is seen that when one of the secondary clocks 9departs from synchronism with the main synchronizing clock 8, theregulating coil 27 thereof is energized by corrective currents operatingto bring the two clocks into synchronism.

Attention is directed to the fact that the corrective eiect of thewinding 27 of each secondary clock 9 is further increased when currentsof relatively high potential are supplied to the line 73-as results whena diil'erence occurs in the rate of operation ofthe main synchronizingclock 8 and the master clock 36.

While I have shown only one form of embodiment of my invention, for thepurpose of.

describing the same and illustrating its principles of construction andoperation and circuit arrangement, it is apparent that various changesand modifications may be made therein without departing from the spiritof my invention, and I desire, therefore, that only such limitationsshall be imposed thereon, as are indicated in the appended claims or asare demanded by the prior art.

I claim:

1. A clock system comprising in combination, a master clock, asynchronizing clock, a main power circuit for actuating saidsynchronizing clock, said main power circuit being under low tensionwhen said clocks are in synchronism, means for impressing high tensionacross said main power circuit, and means including an auxiliary circuitfor controlling said first mentioned means when said synchronizing clockdeparts from synchronism 'with said master clock and when saidsynchronizing clock thereafter regains synchronism with said masterclock.

2. A clock system comprising in combination, a master clock, asynchronizing clock, a main power circuit for actuating saidsynchronizing clock, follow-u mechanism controlled by said synchronizingclock, contacts rotatably mounted and driven by said master clock andada ted to be kept closed by said follow-up mec anism when saidsynchronizing clock is in synchronism with said master clock, anauxiliary circuit controlled by said contacts, and a switch controlledby said auxiliary circuit for maintainin lowy tension across said mainpower circuit W en said contactsv are closed, and for maintaining hightension across said power circuit when said contacts are open.

3. A clock system comprising in combination, a synchronizing c1ock, amaster clock controlling said synchronizing clock, a secondary clock, amain power circuit continuously actuating said synchronizing clock andsaid secondary clock, a secondary power circuit for said secondaryclock, a source of power, and means controlled by said synchronizingclock for causing said secondary powercircuit to be connected to saidsource of power for a predetermined period of time whereby saidsecondary clock may receive power from both of said power circuits.

4. A clock system comprising in combination, a synchronizing clock, asecondary'clock,

a main power circuit for actuating said clocks, a secondary powercircuit for saidsecondary clock, accelerating and retarding means insaid secondary clock, means controlled by said secondary clock forconnecting, disconnecting, and reversing the connection of saidaccelerating and retarding means to said secondar power circuit.

5. A c ook system comprising, in combination, a main power circuit, aclock operatively connected thereto, said clock including a unitcomprising accelerating and retarding means, a secondary circuit, meansfor periodically energizing said secondary circuit, and means foroperatively associating said unit and its accelerating and retardingmeans with said secondary circuit periodically for deiinite timeintervals, said last named means including a switch for alternating theassociated relation of said unit and its accelerating and retardingmeans with said secondary circuit.

6. A clock system comprising, in combination, a main power circuit, asecondary circuit, means for energizing said secondarycircuitperiodically for intervals of definite duration, a clock normallyactuated by energy derived from said main power circuit, acceleratingand retarding means for said clock, said accelerating and retardingmeans comprising a single device, and means to periodically associatesaid accelerating and retarding means as a single device with saidsecondary line so as to periodically control acceleration andretardation of said clock only by electrical energy7 derived from saidsecondary line.

7. clock system comprising, in combination, a main power circuit, aclock adapted to be advanced at a substantially uniform rate by energyderived from said main power circuit, means or affecting the rate ofa-dvancing movement of said clock, a secondary line adapted to beenergized periodically for definite time intervals, and pole changingmeans controlled by said clock for connecting said first-named means tosaid secondary line periodically to cause either faster or slowermovement of said clock.

8. A clock system comprising, .in combination, a main power circuit, asecondary circuit adapted to be energized for predetermined periods, aclock connected -so as to be driven continuously by energy derived fromsaid main circuit, means capable of varying the rate of advancingmovement -of saidA clock, and pole changing means to associate saidlast-named means with said secondary circuit whereby energy derived fromsaid secondary circuit may cause a change in the rate of movement ofsaid clock when said secondary circuit is energized.

9. A clock system comprising, in combination, a main power circuit, aclock, an induction disk motor therefor including a potential coil and aregulating coil deriving electrical energy from said main power circuit,a secondary circuit adapted to be periodically energized, a secondregulating coil, and means for periodically connecting said secondregulating coil to said secondary circuit.

10. A clock system comprising, in combination, a main power c1rcu1t, aclock, an mduction disk motor therefor including a potential coil and aregulating coil continuously connected to said main power circuit, asecond regulating coil for aiecting the rate of advancing movement ofsaid clock, a secondary circuit means for periodically energizing saidsecondary circuit, and switching means for periodically connecting,disconnecting and reversing the relation of said second regulat- 10 ingcoil with said secondary circuit.

11. A clock system comprising, in combination, a main power circuit, aclock operatively connected thereto, said clock including a unitcomprising accelerating and retarding means,

a synchronizing clock, a secondary circuit, an

auxiliaryd Cirguit controlled by said synchronizing clock for causingenergizing of said secondary circuit periodically, and means foroperatively associating said unit with 2o said secondary circuitperiodically .for

definite time periods, said last named means inc luding a switch forreversing the associated relation of said unit with said secondarycircuit.

l2. A clock system comprising, in combination, a main power circuit, asynchronizing clock, a secondary circuit, means controlled by saidsynchronizing clock for energizing said secondary circult periodicallyfor intervals of definite duration, a clock normally actuated by energyderived by said main power circuit, accelerating and retarding means'forsaid clock, and pole changing means controlled by said clock wherebysaid accelerating land retarding-means are associated with saidsecondary circuit soas to periodically control the acceleration andretardation o f said clock only by electrical -energy derived from saidsecondary circuit.

13. A clock system comprising, in combination, a main power circuit, aclock adapted to be advanced at a substantially uniform rate by energyderived from said main power circuit, a secondary circuit, asynchronizing clock, electrically operated means for afecting the rateof advancing movement of said first named clock, means adapted toenergize said secondary line periodically for definite time intervals,and pole changing means controlled by said first named clock forconnecting said electrically operated means to said secondary circuitperiodically to cause either. faster or slower movement of said clock.

14. A clock system comprising, in combination, a main power circuit, asynchronizing clock, ai@ secondary circuit, means controlled by saidsynchronizing clock for energizing said secondary circuit forpredetermined periods, a clock connected so as to be driven continuouslyb y energy derived from said main circuit, means4 capable of varying therate of advance movement of said clock, and pole changing meanscontrolled by said clock to associate said lastx LAURENCE s. HARRISON. 7

